Discitis - An Uncommon, Severe Cause of Back Pain

One of the inevitable problems of aging is the aches and pains that we experience after doing things that we used to do without any consequences. For example, sleeping on a very soft mattress now produces pain in our back as does exercise and even lifting fairly light loads. There are a host of causes of low back pain that include muscle strain, arthritis, herniated disc, muscle spasm, spondylolisthesis (vertebral displacement), some cancers and the list goes on and on. However, there is a back pain cause that I recently encountered that is rare, but requires an astute diagnostician and early treatment to control.

Discitis is a disease, as the "itis" would indicate, of infection of the discs between the vertebra of the spine. Like appendicitis, discitis is usually a bacterial infection but may be viral. The purpose of the disc is to allow some movement and shock absorption of the vertebra that the discs separate in the spinal column. A major issue for the discs is that they do not have a good blood supply and so if bacteria or virus are there, the body's immune cells as well as a physician's antibiotics have great difficulty getting to the infection since they are conveyed there by the blood stream. Thus, if infection of the disc occurs, it is very difficult to treat, and this is why discitis is such a big problem to those who contract it.

Severe, almost unbearable back pain is usually the major symptom. Because, as mentioned at the outset, back pain is common and has a great number of causes, discitis is often misdiagnosed and that means it is late to be appropriately treated and the back pain remains. The pain is usually localized to the region of the infection and does not radiate (shoot) down the leg or other regions of the body as do some other back disorders (like sciatica).

A very thorough history that elicits a fever and chill, indicative of a body-wide infection is the first step in the diagnosis. The best and most sure diagnosis is to have an MRI (magnetic resonance imaging) scan of the region that will show the infection. Blood tests are not particularly specific in the diagnosis but can show infection markers and this is not usually seen with other causes of back pain. After infection is detected by imaging, a culture aspiration may "grow" out of the infection organism. Fever is usually not present once the infection is localized in the disc.

There are two types of discitis. One is the result of an intervention at the site of the infection by a surgical, diagnostic or therapeutic procedure. For example, surgery on the back or a needle placed in the back for a diagnostic or treatment can introduce pathogens. The other form is "spontaneous" discitis that is caused by an infecting organism, either bacterial or viral that comes to the disc by the blood from the urinary tract (kidney or bladder), respiratory track (nose, throat, lungs), intestine, gums (dental work), pelvic infections, or any other entry into the body. This usually causes a generalized blood borne attack that causes the severe fever and chills about a week to ten days prior to the onset of severe back pain.

Discitis occurs in the young and then again in the elderly. The older one is, the greater the chance to have this rare (1 out of 100,000 people) disorder. Diabetes, any immune deficiency, and vascular disease predispose people to this problem. Drug abuse, particularly intravenous drug use and alcoholism are also risk factors.

Discitis is treatable and usually results in an uncomplicated cure. However, it takes a very long course of antibiotic therapy that is usually given intravenously every day at an infusion center. The standard therapy requires six to eight weeks of this intravenous antibiotic therapy. Pain is treated with analgesics and patients learn to move as little as possible, but a brace may be prescribed to enforce this. Activity of parts of the body not affected, like arm exercises, should be done to prevent generalized weakness. Eating a healthy diet and responsible drinking are probably important. The prolonged treatment course and the considerable pain and immobility can lead to situational depression that should be treated if present.

Bottom Line

As we age, one of the rare problems that can occur after a systemic infection is localized and very painful spinal infection of the disc. This is a debilitation and often late-diagnosed problem that requires immediate antibiotic treatment to get the cure that usually does come, but painfully long into the disease.